Buggy code:
public class ReuseExistingTerms implements ComplexQualityMetric { private Model categories = ModelFactory . createDefaultModel ( ) ; private Set < String > topVocabs = new HashSet < String > ( ) ; private ConcurrentMap < String , Double > suggestedVocabs = new ConcurrentHashMap < String , Double > ( ) ; private static Logger logger = LoggerFactory . getLogger ( ReuseExistingTerms . class ) ; private SharedResources shared = SharedResources . getInstance ( ) ; private Set < String > seenSet = MapDbFactory . createFilesystemDB ( ) . createHashSet ( "seen-set" ) . make ( ) ; private List < Quad > _problemList = new ArrayList < Quad > ( ) ; private int overlapClasses = 0 ; private int overlapProperties = 0 ; private int totalClasses = 0 ; private int totalProperties = 0 ; @ Override public void compute ( Quad quad ) { } @ Override public double metricValue ( ) { } @ Override public Resource getMetricURI ( ) { } @ Override public ProblemList < ? > getQualityProblems ( ) { } @ Override public boolean isEstimate ( ) { } @ Override public Resource getAgentURI ( ) { } @ Override public void before ( Object [ ] args ) throws BeforeException { <START_BUG> if ( ( args [ 0 ] ) == null ) { <END_BUG> ReuseExistingTerms . logger . error ( "Argument<seq2seq4repair_space>in<seq2seq4repair_space>the<seq2seq4repair_space>Reuse<seq2seq4repair_space>Existing<seq2seq4repair_space>Vocabulary<seq2seq4repair_space>metric<seq2seq4repair_space>should<seq2seq4repair_space>not<seq2seq4repair_space>be<seq2seq4repair_space>null." ) ; throw new BeforeException ( "Argument<seq2seq4repair_space>should<seq2seq4repair_space>not<seq2seq4repair_space>be<seq2seq4repair_space>a<seq2seq4repair_space>string<seq2seq4repair_space>with<seq2seq4repair_space>a<seq2seq4repair_space>filename." ) ; } String fileName = ( ( String ) ( args [ 0 ] ) ) ; try { categories = RDFDataMgr . loadModel ( fileName ) ; } catch ( RiotException e ) { ReuseExistingTerms . logger . error ( "Error<seq2seq4repair_space>loading<seq2seq4repair_space>configuration<seq2seq4repair_space>file:<seq2seq4repair_space>{}" , fileName ) ; throw new BeforeException ( ( "Invalid<seq2seq4repair_space>configuration<seq2seq4repair_space>file<seq2seq4repair_space>passed<seq2seq4repair_space>to<seq2seq4repair_space>the<seq2seq4repair_space>Reuse<seq2seq4repair_space>Existing<seq2seq4repair_space>Vocabulary<seq2seq4repair_space>metric.<seq2seq4repair_space>The<seq2seq4repair_space>configuration<seq2seq4repair_space>file<seq2seq4repair_space>should<seq2seq4repair_space>be<seq2seq4repair_space>RDF<seq2seq4repair_space>" + ( "(or<seq2seq4repair_space>any<seq2seq4repair_space>other<seq2seq4repair_space>RDF<seq2seq4repair_space>serialisation<seq2seq4repair_space>format),<seq2seq4repair_space>having<seq2seq4repair_space>this<seq2seq4repair_space>following<seq2seq4repair_space>format:<seq2seq4repair_space><http:////linkedgeodata.org><seq2seq4repair_space>:hasDomain<seq2seq4repair_space>\"geographic\"^^xsd:string<seq2seq4repair_space>;<seq2seq4repair_space>" + "<seq2seq4repair_space>:hasVocabularies<seq2seq4repair_space><http:////www.w3.org//2003//01//geo//wgs84_pos#><seq2seq4repair_space>,<seq2seq4repair_space><http:////www.geonames.org//ontology#><seq2seq4repair_space>.<seq2seq4repair_space>" ) ) ) ; } String baseURI = EnvironmentProperties . getInstance ( ) . getBaseURI ( ) ; if ( baseURI == null ) { baseURI = EnvironmentProperties . getInstance ( ) . getBaseURI ( ) ; if ( baseURI == null ) { ReuseExistingTerms . logger . error ( "Unknown<seq2seq4repair_space>Dataset<seq2seq4repair_space>URI" ) ; throw new BeforeException ( "Dataset<seq2seq4repair_space>URI<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>known.<seq2seq4repair_space>This<seq2seq4repair_space>should<seq2seq4repair_space>be<seq2seq4repair_space>set<seq2seq4repair_space>in<seq2seq4repair_space>Luzzu." ) ; } } ReuseExistingTerms . logger . info ( "Getting<seq2seq4repair_space>vocabularies<seq2seq4repair_space>from<seq2seq4repair_space>user<seq2seq4repair_space>configuration<seq2seq4repair_space>file<seq2seq4repair_space>for<seq2seq4repair_space>{}" , baseURI ) ; List < RDFNode > lst = categories . listObjectsOfProperty ( categories . createResource ( baseURI ) , categories . createProperty ( ":hasVocabularies" ) ) . toList ( ) ; ReuseExistingTerms . logger . info ( "Found<seq2seq4repair_space>{}<seq2seq4repair_space>vocabularies" , lst . size ( ) ) ; for ( RDFNode n : lst ) { ReuseExistingTerms . logger . info ( "Loading<seq2seq4repair_space>{}" , n . toString ( ) ) ; VocabularyLoader . loadVocabulary ( n . toString ( ) ) ; suggestedVocabs . put ( n . toString ( ) , 0.0 ) ; } List < RDFNode > lov = categories . listObjectsOfProperty ( categories . createResource ( baseURI ) , categories . createProperty ( ":getFromLOV" ) ) . toList ( ) ; boolean getFromLov = false ; if ( ( lov . size ( ) ) > 0 ) getFromLov = lov . get ( 0 ) . asLiteral ( ) . getBoolean ( ) ; if ( getFromLov ) { List < RDFNode > domainNode = categories . listObjectsOfProperty ( categories . createResource ( baseURI ) , categories . createProperty ( ":hasDomain" ) ) . toList ( ) ; for ( RDFNode n : domainNode ) { try { List < String > vocabs = LOVInterface . getKnownVocabsPerDomain ( n . asLiteral ( ) . getString ( ) ) ; for ( String v : vocabs ) suggestedVocabs . put ( v , 0.0 ) ; } catch ( IOException e ) { ReuseExistingTerms . logger . error ( "Could<seq2seq4repair_space>not<seq2seq4repair_space>load<seq2seq4repair_space>vocabularies<seq2seq4repair_space>from<seq2seq4repair_space>LOD.<seq2seq4repair_space>Error<seq2seq4repair_space>Message:<seq2seq4repair_space>{}" , e . getMessage ( ) ) ; } } } } @ Override public void after ( Object [ ] args ) throws AfterException { } }

Fix:
if ( ( ( args != null ) && ( ( args . length ) > 0 ) ) && ( ( args [ 0 ] ) == null ) ) {